Reamer-spring pilot guide



0a. 1, 1929. F, w, BECKER 1,729,862

REAHER SPRING PILOT GUIDE Filed Dec. 24, 1925 INVENTOR finale/2M If. 5801c? RW0\ b-Q ..ATTORNEY Patented Oct. 1, 1929 UNITED STATES PATENT OFFICE FREDERICK W. BECKER, OF ALBANY, NEW YORK, ASSIGNOR '10 WATERVLIET TOOL COMPANY, INC., A CORPORATION OF NEW YORK REAMER-SPRING PILOT GUIDE Application filed December24, 1925. Serial No. 77,651.

My present invention relates to an improvement in reamers of the class known as line reamers, and more especially to means whereby such reamers as are in practice guided in alinement through adJacent or alined bores which have been rough drilled, which improvement is more specifically known as a guiding pilot.

One of the advantages of my device is that due to the construction of the reamer pllot herein, variations in the bore of the hole due to rough drilling or in other instances due to the wear of the shaft member thereln, which would consequently cause the hole to become partially oval, the pilot will care for such variations, permitting the reamer to average its out so that during the reamin or smoothing process, the reamer is guided in perfect alinement through the holes being treated.

Other advantages will be disclosed as the bores and being centered in this bore and guided by the pilot which is located in the oppositely related bore, for provldlng alined reaming of the bores.

Another object is to provide a pllot for a reamer used for reaming a bore open at each end, the reamer operating from one end of the bore and being centered in the bore and guided by the pilot located in the opposite end of the bore.

I attain these and .such otherobjects as may later appear herein, by the device one of the possible embodiments of which 1s lllustrated in the accompanying drawing and described in the subjoined specification.

In the drawing:

Fig. 1 is a view of a reamer with my device in operation in a section of a piston and showing one way of using the devlce.

Fig. 2 is a fragmentary sectional View of the piston showing the reamer entering the hole or bore on one side of the piston on the inner side of the piston, and the pilot located in the hole or bore on the opposite outer side of the piston.

Fig. 3 is a side View showing the details of the pilot, with a portion of the pilot broken out to show the interior thereof.

Similar reference characters denote similar arts throughout the several views.

y device comprises a reamer pilot which is slidably and rotatably mounted upon the shank of a reamer of any standard sort, and comprises a substantially cylindrical member made preferably of tool steel and spring tempered.

As shown in Fig. 3, it has a rear solid extension 1, which is preferably knurled as at 2 whereby the pilot may be readily handled for positioning. The forward end of the pilot is provided with a plurality of longitudinally extending cuts 3 which divide the pilot member into a number of resilient ngers 4, these fingers being comparatively thin in cross section as indicated at X. Near their outer ends these fingers are provided with a bead-like portion generally denoted by 5. i The fingers thus formed are extremely resilient.

The solid end 1 of the pilot is bored as at B, Fig. 3,to slidably and rotatably receive therein the shank S of any standard reamer, and the forward bore denoted by the dotted lines Z is of a larger diameter and terminates at the shoulder G, the bore Z being formed by the interiors of the fingers.

In use a reamer may be started in the hole or bore from the side G in Fig. 1 of the piston, and the shank S passed through the opposite bore M, thereby permitting the side shank S to protrude on the right side of the piston R. The pilot member 1 is passed over the shank S as shown and owing to the fact that the bead portions 5 constitute a portion of the pilot which in cross-section is somewhat larger or oversize relative to the bore being reamed, the bead portions 5 engage the interior surface of the bore M and are slightly compressed to the amount of discrepancy between the normal diameter of and this cross-section of the pilot and the diameter of the bore being reamed. The pilot is pressed inwardly as shown in Fig. 1, until its tapering face contacts with the edge of the bore M as at L. This leaves the outer shank S of the reamer supported in alining position with its coordinating wrist pin hole on the G side of the piston, and by means of a wrench or any other suitable type of turning device, the reamer is rotated and fed through the piston bores until it reaches the opposite side and enters a slight amount after which the spring pilot guide is removed and placed on the opposite or G side of the piston as shown in Fig. 2, and the operation of the reaming in the direction of the arrows continued until the reamer has passed through the bore completely and reamed both holes to the desired size and in perfect alinement.

While the operation of the pilot in association with a reamer for reaming a continuous hole or bore open at each end is not shown in the drawing, the operation is readily understood from Figs. 1 and 2 and the operation hereinbefore described for reaming oppositely disposed bores, the continuous bore being considered as extending through solid material connecting the op positely related bored portions of the piston, the reamer operating at one of the open ends of the bore and the shank S extending through said bore and being slidably movable in the pilot located in the opposite end of the bore, the operation then being the same as for aliningly reaming oppositely disposed bores.

It is obvious that these spring pilots may be made any desired size, to fit the desired reamer sizes, both as to shank and bore diameter, and it is also obvious that preferably the spring fingers 4 of the pilot andintegral bead 5 thereon are made of a slightly larger size than the hole to be reamed, so that the beading will be snugly held in the hole while the reaming process is taking lace.

What I claim is:

1. The combination, with a reamer having an extending shank, of a reamer pilot having a portion engageable in the here to be reamed and provided with a bore for slidably receiving therein said shank for supporting the shank and having a portion consisting of a plurality of compressible fingers, the interior sices of said fingers providing a bore portion of the pilot of greater diameter than the bore of said shank supporting portion and communicating with the bore of the shank supporting portion, said fingers having at their free ends enlargements forming a beaded portion of the pilot, the pilot in crosssection at said beaded portion being somewhat greater in diameter than the bore to be reamed and said finger portion, said finger portion being engageable with the margin of said hole for compression, said beaded portion when engaged in the bore to be reamed permitting passage of said shank through the bore portion of the pilot formed by the compressible fingers, said finger and shank supporting portions tapering from a point adjacent to said beaded portion to the free end of the shank supporting portion, said beaded portion diameter being substantially equal to said margin contacting finger portion diameter when said fingers are compressed.

2. A device for guiding a reamer having a forwardly extending cylindrical shank into a hole of irregular cross-section, said device comprising a body portion provided with a bearing bore fitting on said shank; and a plurality of resilient fingers formed on the inner end of said body portion spaced from said shank and pointing toward the reamer; the outer face of said fingers being formed near the free ends of the fingers with headlike portions respectively engageable with the intermediate part of the interior of the hole for substantially centering the reamer;

with that part; the intermediate part of the outer face of said fingers adapted to be compressed by operative, engagement with the margin of said hole whereby the bead-like portions are converged to provide a conical portion adapted to wedge in the end of the hole for substantially centering the reamer at said part, whereby by centering the reamer at two parts, the reamer is substantially alined with the axis of the hole.

3. The combination with a reamer having an extended shank, of a reamer guide including a shank guiding portion having a bore for slidably rotatable engagement of said shank therein, and a shank positioning ortion disposed on one end of the shank gui ing portion and free at its end opposite the shank guiding portion and having a hollow interior forming a bore communicating with the bore of the shank guiding portion, said shank positioning portion being resiliently compressible by operative en agement with the margin of a hole in which said guide is disposed and having on the exterior of its free end outwardly extending means .engagealole, upon said compression of the shank positioning portion, with the interior surface of said hole to be reamed, the part of the shank positioning portion lying between said'outwardly extending means and the end of the shank positioning portion adjacent to the shank guiding portion assuming a substantially truncated cone shape when the shank positioning portion is .compressibly engaged by the margin of said hole so that said outwardly extending means engages the interior surface of said hole inwardly of the mouth of the hole, the end of said shank extending from the bore of the shank guiding portion being slidably rota-tably "engaged in said interior FREDERICK W. BECKER. 

